1. Field
Exemplary embodiments relate to thin film transistors (“TFTs”), methods of manufacturing the same and display devices including the same. More particularly, exemplary embodiments relate to TFTs using an oxide semiconductor as an active layer, methods of manufacturing the same and display devices including the same.
2. Description of the Related Art
A conventional thin film transistor (“TFT”) having a bottom gate structure may include a gate electrode on a substrate, a gate insulation layer on the gate electrode, and an active layer formed on the gate insulation layer and superimposed on the gate electrode. The TFT may further include a source electrode and a drain electrode contacting the active layer.
As for the conventional TFT, the active layer may include a semiconductor material such as amorphous silicon or polysilicon. However, when the active layer includes amorphous silicon, a display device may have a low operational speed due to reduced charge mobility in the active layer. When the active layer includes polysilicon, a uniform threshold voltage of the TFT may not be obtained despite a high operation speed.
Recently, an oxide semiconductor including a metal oxide is utilized for the active layer in order to overcome the aforementioned problems.